Marriage proposal via a scientific paper may not be everyone’s idea of romance, but for two physics grad students, it was the perfect medium.

On Sunday, Reddit user bogus_wheel (whose real name is Christie Nelan) posted a scientific proposal online authored by her then-boyfriend Brendan McMonigal, entitled “Two Body Interactions: A Longitudinal Study.” The paper summarizes their meeting and relationship of more than seven years, finally concluding that happiness was likely to increase over time.

The pair both originally met at the University of Sydney while pursuing degrees in physics. In a graph showing the correlation between happiness and time, Brendan McMonigal writes in his conclusion:

The summary of the findings of the study are presented in Figure 1, and show that the projected happiness is upward with high confidence. Taking these results into account, the author proposes to Christie Nelan the indefinite continuation of the study. The subject’s response to this proposal should be indicated below.

McMonigal actually sent Nelan the proposal last March, on the seven-year anniversary of their relationship; but it was only recently that Nelan decided to post it online.

Erica Ho was previously a reporter for TIME in Hong Kong where she wrote about technology, pop culture and Asian international affairs. Before that, she worked at Gizmodo, Lifehacker and AOL. She now currently runs Map Happy, a travel-oriented site.